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21st AIAA International Space Planes and Hypersonics Technologies Conference, Hypersonics 2017

作者： Jiang, Li Shi, Aiming Qin, Zhixuan NPU-Duke Joint Research Laboratory for Light Pressure Propulsion Solar Sail-Craft Dynamics National Key Laboratory of Science and Technology on Aerodynamic Design and Research Northwestern Polytechnical University National Key Laboratory of Aerodynamic Design and Research Box 114 No.127 West Youyi Road Xi’anShaanxi710072 China

ISBN: (数字)9781624104633

ISBN: (纸本)9781624104633

The concept of solar sailing using sunlight propelling thin membrane structure has been proposed for a long time. The principle of this technology is accumulating velocity to reach a very high speed which may up to 10% speed of light based upon the fact that object could be consistently accelerated even by a tiny force in outer space environment. In 2010, solar sailing was confirmed by IKAROS of JAXA. In this paper, two kinds of propulsive mechanism are mentioned. One propulsive way is based upon the momentum exchange of photons and solar sails. The other propulsive scheme which uses special-made graphene material emitting electrons exhibits a great potential. The former scheme based upon momentum exchange is relatively persistent and stable but requires a large reflecting surface area at the same time. The latter scheme could provide a several orders larger propulsive force although there are engineering difficulties need to be overcome. The values of acceleration due to two propulsive schemes respectively are compared to illustrate the propulsive efficiency. It is believed that if the latter technology matures and these two propulsive ways could be combined comprehensively, a combined light propelling system with better performance would be possible in the future. © 2017, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved.

关键词： Solar sails

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design and Analysis of All-electric Aircraft Nose Wheel Steering system Based on Intelligent Algorithm

Design and Analysis of All-electric Aircraft Nose Wheel Stee...

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2017 2nd International Conference on Applied Mechanics and Mechatronics Engineering(AMME 2017)

作者： Ming ZHANG Meng-jiao LENG Xin WU Key Laboratory of Fundamental Science for National Defense-Advanced Design Technology of Flight Vehicle Nanjing University of Aeronautics & Astronautics Aviation Key Laboratory of Science and Technology on Aero Electromechanical System Integration

As all-electric aircraft has many advantages, aircraft nose wheel steering system would be developed to the all-electric direction. Aiming at the control demand of nose wheel steering system, based on the basic principles of nose wheel steering system and the design technique of mechanotronics, an all-electric aircraft nose wheel steering system composed of a nose wheel steering mechanism of two worm gear and a control servo system of fly-by-wire having both steering and anti-shimmy function is designed to meet the demand for operation control in nose wheel steering system. Besides, the fuzzy algorithm and BP neural network algorithm is applied to the control system to explore its algorithm. Then based on Matlab/Simulink and LMS/AMESim software, the united simulation model of the system with fuzzy PID controller is established to make the dynamic simulation analysis for the verification of its steering function, the research results indicate that the nose wheel steering system is reasonable and validated, can meet the requirements of the general project.

关键词： Mechanotronics design United simulation analysis Nose wheel steering system Landing gear

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Implementation of dual time-stepping strategy of the gas-kinetic scheme for unsteady flow simulations

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Physical Review E 2017年第5期95卷 053307-053307页

作者： Ji Li Chengwen Zhong Yong Wang Congshan Zhuo National Key Laboratory of Science and Technology on Aerodynamic Design and Research Northwestern Polytechnical University Xi'an Shaanxi 710072 China

In our study, the dual time-stepping strategy of the gas-kinetic scheme is constructed and used for the simulation of unsteady flows. In comparison to the previous implicit gas-kinetic scheme, both the inviscid and viscous flux Jacobian are considered in our work, and the linear system of the pseudo-steady-state is solved by applying generalized minimal residual algorithm. The accuracy is validated by several numerical cases, the incompressible flow around blunt bodies (stationary circular cylinder and square cylinder), and the transonic buffet on the NACA0012 airfoil under hybrid mesh. The numerical cases also demonstrate that the present method is applicable to approach the fluid flows from laminar to turbulent and from incompressible to compressible. Finally, the case of acoustic pressure pulse is carried out to evaluate the effects of enlarged time step, and the side effect of enlarged time step is explained. Compared with the explicit gas-kinetic scheme, the proposed scheme can greatly accelerate the computation and reduce the computational costs for unsteady flow simulations.

关键词： Aerodynamics Compressible flows Shock waves

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Unexpectedly High Salt Accumulation inside Carbon Nanotubes Soaked in Dilute Salt Solutions

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Physical Review Letters 2018年第22期121卷 226102-226102页

作者： Xueliang Wang Guosheng Shi Shanshan Liang Jian Liu Deyuan Li Gang Fang Renduo Liu Long Yan Haiping Fang Center for Thorium Molten Salt Reactor System Shanghai Institute of Applied Physics Chinese Academy of Sciences Shanghai 201800 China University of Chinese Academy of Sciences Beijing 100049 China Division of Interfacial Water Key Laboratory of Interfacial Physics and Technology and Shanghai Synchrotron Radiation Facility Shanghai Institute of Applied Physics Chinese Academy of Sciences Shanghai 201800 China Shanghai Applied Radiation Institute and Department of Physics Shanghai University Shanghai 200444 China School of Physical Science and Technology ShanghaiTech University Shanghai 201210 China

We experimentally demonstrate the formation of salt aggregations with unexpectedly high concentration inside multiwalled carbon nanotubes (CNTs) soaked only in dilute salt solution sand even in solutions containing only traces of salts. This finding suggests the blocking of fluid across CNTs by the salt aggregations when CNTs are soaked in a dilute salt solution with the concentration of seawater or even lower, which may open new avenues for the development of novel CNT-based desalination techniques. The high salt accumulation of CNTs also provides a new CNT-based strategy for the collection or extraction of noble metal salts in solutions containing traces of noble metal salts. Theoretical analyses reveal that this high salt accumulation inside CNTs can be mainly attributed to the strong hydrated cation-π interactions of hydrated cations and π electrons in the aromatic rings of CNTs.

关键词： Chemical Physics & Physical Chemistry Physisorption Surface & interfacial phenomena

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Flatbands and Emergent Ferromagnetic Ordering in Fe3Sn2 Kagome Lattices

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Physical Review Letters 2018年第9期121卷 096401-096401页

作者： Zhiyong Lin Jin-Ho Choi Qiang Zhang Wei Qin Seho Yi Pengdong Wang Lin Li Yifan Wang Hui Zhang Zhe Sun Laiming Wei Shengbai Zhang Tengfei Guo Qingyou Lu Jun-Hyung Cho Changgan Zeng Zhenyu Zhang International Center for Quantum Design of Functional Materials (ICQD) Hefei National Laboratory for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics University of Science and Technology of China Hefei Anhui 230026 China CAS Key Laboratory of Strongly-Coupled Quantum Matter Physics and Department of Physics University of Science and Technology of China Hefei Anhui 230026 China Department of Physics and HYU-HPSTAR-CIS High Pressure Research Center Hanyang University 17 Haengdang-Dong SeongDong-Ku Seoul 133-791 Korea National Synchrotron Radiation Laboratory University of Science and Technology of China Hefei Anhui 230029 China Department of Physics Applied Physics and Astronomy Rensselaer Polytechnic Institute Troy New York 12180 USA Anhui Key Laboratory of Condensed Matter Physics at Extreme Conditions High Magnetic Field Laboratory and Hefei Science Center Chinese Academy of Sciences Hefei 230031 China Collaborative Innovation Center of Advanced Microstructures Nanjing University Nanjing 210093 China

A flatband representing a highly degenerate and dispersionless manifold state of electrons may offer unique opportunities for the emergence of exotic quantum phases. To date, definitive experimental demonstrations of flatbands remain to be accomplished in realistic materials. Here, we present the first experimental observation of a striking flatband near the Fermi level in the layered Fe3Sn2 crystal consisting of two Fe kagome lattices separated by a Sn spacing layer. The band flatness is attributed to the local destructive interferences of Bloch wave functions within the kagome lattices, as confirmed through theoretical calculations and modelings. We also establish high-temperature ferromagnetic ordering in the system and interpret the observed collective phenomenon as a consequence of the synergetic effect of electron correlation and the peculiar lattice geometry. Specifically, local spin moments formed by intramolecular exchange interaction are ferromagnetically coupled through a unique network of the hexagonal units in the kagome lattice. Our findings have important implications to exploit emergent flat-band physics in special lattice geometries.

关键词： Electronic structure Ferromagnetism Kagome lattice Angle-resolved photoemission spectroscopy Density functional theory First-principles calculations Magnetization measurements Scanning tunneling microscopy Scanning tunneling spectroscopy Tight-binding model

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Semantic-driven method for designing 3D busbars

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Computer Aided Drafting,design and Manufacturing 2017年第2期27卷 16-23页

作者： Shi Kanle Zhu Zixu Wu Zijian Zhang Hui Yong Junhai School of Software Tsinghua University Key Laboratory for Information System Security Ministry of Education of China Tsinghua National Laboratory for Information Science and Technology

Traditional busbar design is inefficient, costly, and error-prone because of frequent changes of requirements. This paper proposes a semantic-driven method for designing 3D busbars to solve this problem. The design process contains two main parts, namely, semantic-driven routing design and automatic routing segmentation. Semantic-driven routing design creates a relation table between electrical semantics and 3D modeling parameters, as well as helps designers create routings efficiently using electrical parameters as input. Automatic routing segmentation can convert routings into busbar segments that also include manufacturing information. Because the design operations are associated with one another, the resulting busbars can automatically be changed in real time when requirements are changed.

关键词： semantic-driven design busbar design busbar segmentation modeling change of requirement

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Automatic wiring method for switchgear design

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Computer Aided Drafting,design and Manufacturing 2017年第2期27卷 32-38页

作者： Shi Kanle Gao Ying Wu Zijian Zhang Hui Yong Junhai School of Software Tsinghua University Key Laboratory for Information System Security Ministry of Education of China Tsinghua National Laboratory for Information Science and Technology

An automatic 3D wiring method for switchgear design is proposed in this paper. First, wiring constraints are created, and a corresponding evaluation model is proposed. Then, based on the structure of the cabinet, we propose a contour expansion scheme to construct rough paths. Different wiring features of the switchgear are used to connect rough local paths. All the paths are represented in a uniform data structure and forma path network. Finally, an improved A* algorithm is used to search the wiring path between the components in the routing network; the evaluation model is considered as heuristic rules for path searching. The result can satisfy the practical requirements of switchgear design. Experimental results are also provided.

关键词： wiring method path searching contour expansion switchgear design A* algorithm

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Soft Robots: Fast‐Response, Stiffness‐Tunable Soft Actuator by Hybrid Multimaterial 3D Printing (Adv. Funct. Mater. 15/2019)

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Advanced Functional Materials 2019年第15期29卷

作者： Yuan‐Fang Zhang Ningbin Zhang Hardik Hingorani Ningyuan Ding Dong Wang Chao Yuan Biao Zhang Guoying Gu Qi Ge Digital Manufacturing and Design Centre Singapore University of Technology and Design Singapore 487372 Singapore Soft Robotics and Biodesign Lab Robotics Institute School of Mechanical Engineering Shanghai Jiao Tong University Shanghai 200240 China State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong University Shanghai 200240 China Science and Math Cluster Singapore University of Technology and Design Singapore 487372 Singapore

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On-Line Monitoring Method for Fatigue of Mechanical Structure Parts

On-Line Monitoring Method for Fatigue of Mechanical Structur...

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2017 2nd International Conference on Energy, Power and Electrical Engineering(EPEE 2017)

作者： Xi-qiang MA Fang YANG Yu-jun XUE Ji-shun LI Henan Key Laboratory for Machinery Design and Transmission System Henan University of Science and Technology School of Mechatronics Engineering Henan University of Science and Technology

Fatigue failure was a typical failure form of mechanical structure parts, elastic modulus drop was an important characteristic of structural material occur fatigue, so a new mechanical structure fatigue monitoring online method was proposed. Firstly, a test device that could impose cyclic load with adjustable frequency and amplitude on cantilever beams was designed;secondly, a stress measurement system based on Fiber Bragg Grating sensor to monitor structural state of fatigue was developed;thirdly, a method to calculations stress based on this system was described;finally, the online method was used in the elastic modulus drop.

关键词： Fiber Bragg grating sensor Fatigue monitoring Cyclic loading

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Scaling analysis and SE simulation of the tilted cylinder-interface capillary interaction

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IOP Conference Series: Materials science and Engineering 2018年第1期372卷

作者： S Q Gao X Y Zhang Y H Zhou National Key Laboratory of Science and Technology on Reactor System Design Technology Nuclear Power Institute of China Chengdu 610041 China Department of Mechanics and Engineering Sciences College of Civil Engineering and Mechanics Lanzhou University Lanzhou 730000 China

The capillary interaction induced by a tilted cylinder and interface is the basic configuration of many complex systems, such as micro-pillar arrays clustering, super-hydrophobicity of hairy surface, water-walking insects, and fiber aggregation. We systematically analyzed the scaling laws of tilt angle, contact angle, and cylinder radius on the contact line shape by SE simulation and experiment. The following in-depth analysis of the characteristic parameters (shift, stretch and distortion) of the deformed contact lines reveals the self-similar shape of contact line. Then a general capillary force scaling law is proposed to incredibly grasp all the simulated and experimental data by a quite straightforward ellipse approximation approach.

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